Insidah's Instruction recipe

In a blender, add the Kilkenny and Grolsh Beer. Blend the two ingredients for approximately 10 seconds to reduce fizz and bubble content. Add Heineken straight from the bottle into the beer glass at the same time as the Grolsch/Kilkenny blend.

Beer will remain somewhat smoother than normal, with a much refined aftertaste. The blend itself is less bubbly which means that there will be less "burps" and therefore will allow more consumption...
Leave a slight head, and allow to settle for about 30 seconds before serving. Colour will be just a tad darker than normal yellow/white beer due to the Kilkenny.

Note: Do not operate blenders whilst intoxicated.